The title compound, (4S,5S,8R, IOZ)-2,2,5,6,8,10-hexamethyl-4-phenyl- 1,3-dioxa-6-aza-2-silacycloun-dec-10-en-7-one, crystallizes with two virtually identical molecules in the asymmetric unit, each with the same absolute configuration. Bond distances and angles are normal; the closest approaches across the ring between non-bonded atoms are all greater than 3.35 .A,. The amide and enol ether groups are planar
to within +- 0.06 A.